Xenpak 10GB LRXenpak 10gb lr is single mode Cisco fiber optic transceiver for 10G Ethernet, xenpak 10gb lr max working distance is 10km over common single mode G 652 optical fiber. Xenpak 10gb lr use duplex SC fiber optic interface to connect the network, the other end of the xenpak 10gb lr transceiver will fit into the relevant slot or port on the switch or routers.